The present invention relates to a preventive structure for permanent strain of a terminal in which a support piece is disposed on a flexed portion of an elastic contact member of a female terminal in order to prevent the elastic contact member from being flexed excessively.
Now, FIG. 7 shows a conventional preventive structure for permanent strain of a terminal which is disclosed in Japanese Utility Model Publication No. Hei 7-42005.
According to the conventional preventive structure for the permanent strain of the terminal, within a rectangular tube-shaped electric contact part 2 of a female terminal 1, on the lower side of an elastic contact piece 3 serving as an elastic contact member, a support piece 5 is formed by raising up the same vertically from a bottom wall 4, and the leading end portion of the support piece 5 is disposed opposed to the lower side surface of the elastic contact piece 3, whereby, when the elastic contact piece 3 is flexed, the lower side surface of the elastic contact piece 3 is contacted with the leading end portion of the support piece 5 to thereby prevent not only the excessive flexure of the elastic contact piece 3 but also the permanent strain thereof caused by the excessive flexure.
On the both sides of the support piece 5, there are formed projections 6 and, in the side walls 7 of the electric contact part 2, there are formed engagement holes 8 into which the projections 6 can be engaged respectively. If the projections 6 are engaged with the engagement holes 8, then such engagement between them can prevent the support piece 5 from falling down. Thanks to this, as shown in FIG. 8, even if a male terminal 9 is inserted forcibly into the electric contact part 2, the support piece 5 supports the elastic contact piece 3 to thereby prevent the elastic contact piece 3 from being flexed excessively.
However, in the above-mentioned conventional preventive structure for the permanent strain of the terminal, because the range of the elastic contact piece 3 supported by the support piece 5 is nothing but the range that corresponds to the thickness of the support piece 5, if an excessive load is applied to the other portions of the elastic contact piece 3 than the supported portion (range) thereof in the pushing direction by the male terminal 9 or by a probe pin (not shown) for conduction check or a jig rod (not shown), then the elastic contact piece 3 can be flexed or deformed into permanent strain.
In particular, as shown in FIG. 9, when the support piece 5 is disposed on the base side of the elastic contact piece 3, if the male terminal 9 or the like is forcibly inserted into the deep side of the support piece 5, then the elastic contact piece 3 is deformed with the support piece 5 as a fulcrum thereof. On the other hand, as shown in FIG. 10, when the support piece 5 is disposed in the vicinity of the intermediate portion of the elastic contact piece 3, if the male terminal 9 or the like is forcibly inserted into the front side of the support piece 5 at a large inclination angle, then the elastic contact piece 3 is deformed in such a manner that the base side thereof is depressed.